ESE's works engine tuner

[wax]

So no one has tried e85 then

[TZ350]

So no one has tried e85 then

E85 is currently illegal for Bucket racing here in NZ under the no alcohol rule. .... so no, no one here has tried the forbidden fruit right .... .......



E85 ... I have no experience with it myself but a Guy who runs it in an air cooled 350cc 2T VMX bike tells me that when the engine gets hotter than 70degC you have to richen up. So you either run around for the first 2-3 laps rich as hell then fine for the rest of the race or you get in 3 good laps and then risk detonation for the rest of the time you are out there, the choice is yours. 4T's with O2 sensors don't seem to have this problem. Temperature switchable power jet might be an answer for air cooled 2T's.

From what I hear, E85 does not make anymore power than petrol but there might be reliability advantages from the extra cooling if a 2T can be run rich, maybe splash in a bit of methanol too if you can because it likes being run rich.

[F5 Dave]

Or an Intelejet system coupled to an Intelligent rider to adjust it.

[2T Institute]

E85 is currently illegal for Bucket racing here in NZ under the no alcohol rule. .... so no, no one here has tried the forbidden fruit right .... .......



E85 ... I have no experience with it myself but a Guy who runs it in an air cooled 350cc 2T VMX bike tells me that when the engine gets hotter than 70degC you have to richen up. So you either run around for the first 2-3 laps rich as hell then fine for the rest of the race or you get in 3 good laps and then risk detonation for the rest of the time you are out there, the choice is yours. 4T's with O2 sensors don't seem to have this problem. Temperature switchable power jet might be an answer for air cooled 2T's.

From what I hear, E85 does not make anymore power than petrol but there might be reliability advantages from the extra cooling if a 2T can be run rich, maybe splash in a bit of methanol too if you can because it likes being run rich.

I have found the opposite, as little as 10-15% e85 in ULP will make a air or water cooled engine run far cooler and with the alcohol won't detonate (can still have lean seizures).

[TZ350]

I have found the opposite, as little as 10-15% e85 in ULP will make a air or water cooled engine run far cooler and with the alcohol won't detonate.

I was only relating what I had been told and if a 2T does run cooler that is very interesting, certainly worth looking at.

[DoldGuy]

Peter, you might also ask Wob about the combination of a longer rod and a higher-placed gudgeon pin. That's what I would be looking for.

Frits,

Help a slow learner like me understand why you would prefer the longer rod with the pin higher in the piston.

Is this just for the reduction in angle...longer/ less dwell at TDC / BDC...more leverage?

Again, thanks for sharing your knowledge.

[DoldGuy]

The case volume would only need changing alot if you are looking for a big top end boost as I was looking for using a KTM for kart roadracing.
One model of KTM 250 has a 130 rod and I used a Vertex CR250 single ring race piston.
Yes,Frits is right ,all the 250 now have the same bore and stroke so anything will fit.
This combo needed an 8mm plate, and that gave a good case increase along with a plate behind the reed so I could fit in a VF4 from a later model KTM.

Wobbly,

I have seen / saved pictures of the KTM you have posted & see the massive amount of work you did on the sub exhaust ports, along with the floor (75% of the area?).

Is there any more information available on this build...results / videos of this kart? Currently working on a KTM & gathering as much knowledge as possible, these KTMs have a lot of parts crossover, like the rod selections 135/132/129/125 and would change the case volume a little or a lot depending on rod / piston choices.

Thanks for sharing info.

[Fabio15]

has anyone here tried e85 in their bikes and taken the time to jet it in correctly. What was the result. did you get a power gain. was the engine more reliable due to it being a higher octane and a colder burning fuel.
Do you recut the combustion chamber becuase of the new fuel burn properties

Adegnes has:


https://m.youtube.com/user/TheAdegnes


https://m.youtube.com/results?q=2%20...0stuffing&sm=1

https://m.youtube.com/watch?v=MbfQpjWMQN0

[speedpro]

e85 is ethanol. I only have experiance with methanol but to an extent there are similarities. One of the similarities of interest is the latent heat of evaporation. High performance 2-strokes are fuel cooled. Petrol absorbs a certain amount of heat as it evaporates. Methanol, and probably ethanol, absorbs heaps more. A big blown methanol V8 will have frost form very quickly on the blower and manifiold at idle(3000rpm). The more heat the fuel can remove from the engine the better, obviously, and ethanol absorbs a fair amount more than petrol. Methanol from experiance absorbs heaps.
Run the engine rich and it absorbs even more plus you get the advantage of a buildup of detonation resistance. Trust me it will still detonate if you try hard enough but no worse then petrol in that regard.
2-strokes stand to benefit substantially from being allowed to use ethanol or methanol. Heaps of compression and cooling being the factors. Without pretty much unobtainable compression, or boost, 4-strokes will not gain a similar benefit.

[jbiplane]

Maybe. Doubtful if there will be any brainstorm good enough to create a smallish exhaust capable of generating the same power as the huge expansion pipes, but something on the order of 2/3 - 3/4 the power might suit some applications.

I use 2 (warez can be found on torrents) "Lotus engine simulation" and "Ricardo Vawe" to make small enough exhaust.
Other idea try ro read about 1/4 vawe mufflers (different trade names, like "magic mufflers"). They are 2 times shorter
than classical resonators and produce much wider powerband with a bit less max power.

[Frits Overmars]

Frits,Help a slow learner like me understand why you would prefer the longer rod with the pin higher in the piston. Is this just for the reduction in angle...longer/ less dwell at TDC / BDC...more leverage?

Leverage is not my main concern and neither is dwell time at TDC/BDC; the variation would be minuscule.
Reduction in con rod angle and a corresponding reduction in friction is one good reason. Crankcase volume is another one. But my main reason is piston mass.
The bulk of a piston's mass is concentrated between its crown and the gudgeon pin holes. Raise the pin and you'll lighten the piston, simple as that.
This does not even depend on con rod length. It's true that I prefer a long con rod, but I would prefer a high piston pin in combination with any rod length.
And don't worry about the piston tipping over. Just look below at the piston hight, or rather lack of it, that four-strokes get away with. And two-stroke piston skirts are invariably longer than their four-stroke counterparts because when in TDC, they must keep the exhaust port closed.

[lohring]

So no one has tried e85 then

We tested a lot of different fuels on an industrial style 26 cc racing engine. Because we could only change the mixture and ran the same pipe for all tests, there was very little power difference. The mixture needs to be richened for alcohol containing fuel. Below is the report.

Lohring Miller

[nitro2tfx]

We tested a lot of different fuels on an industrial style 26 cc racing engine. Because we could only change the mixture and ran the same pipe for all tests, there was very little power difference. The mixture needs to be richened for alcohol containing fuel. Below is the report.

Lohring Miller

15% nitro with no power increase and in fact arguably a power loss, is an interesting result, yet not quite as interesting as the time we put 40% nitro into a fuel concoction and had no power change and jetting/timing wouldn't fix it lol. Nitro is an anomaly in many, many ways. Under the right conditions it is amazing and under the wrong conditions it is neutered.

[Haufen]

Leverage is not my main concern and neither is dwell time at TDC/BDC; the variation would be minuscule.
Reduction in con rod angle and a corresponding reduction in friction is one good reason. Crankcase volume is another one. But my main reason is piston mass.
The bulk of a piston's mass is concentrated between its crown and the gudgeon pin holes. Raise the pin and you'll lighten the piston, simple as that.
This does not even depend on con rod length. It's true that I prefer a long con rod, but I would prefer a high piston pin in combination with any rod length.
And don't worry about the piston tipping over. Just look below at the piston hight, or rather lack of it, that four-strokes get away with. And two-stroke piston skirts are invariably longer than their four-stroke counterparts because when in TDC, they must keep the exhaust port closed.

I agree with you, and I would like to add one thing: moving the pin up increases the temperature the pin is subject to. After moving the pin up, I was able to repeatedly convert once silver colored piston pins to a nice blueish tan instead. So if anyone thinks about this modification, check your pin first. If it is alread showing signs of heat impact, then maybe there is not that much to gain.

From gut feeling I'd say everything at and above a compression height of 25mm is going to be fine.

[F5 Dave]

I've always thought moving that amount of mixture under the piston is unproductive. Shorter crown to pin heights have proven beneficial every time so far.